DO port for digital output, AO port for analog output.Size:37x25x32mmWeight: 15 gConnector: +5Vcc - GND - VRx - VRy - SWMaterial: ABS plastic PS2 game joystick module suits for Arduino, connects to two analog inputs, the robot is at your commands with X,Y control. It also has a switch that is connected to a digital pin, convenient to use.